摘要
以Spangler-lowa方法为理论基础,结合有限元建模、统计分析、数学拟合及试验验证等方法,对含缺陷管道外载荷承载能力、内压承载能力开展研究。对于完好管道的外载荷承载能力评价,采用Spangler-lowa方法计算得到管道水平直径变形量,然后求得管道水平直径变形率。当管道水平直径变形率超过3%时,认为管道失效。含均匀腐蚀缺陷的管道外载荷承载能力评价:对小管径管道(外直径≤700 mm),可根据GB 50028—2006规定的最小公称壁厚评价;对大管径管道(外直径> 700 mm),应该按照Spangler-lowa方法的计算结果进行评价。点蚀缺陷对受外载荷影响的管道变形影响不大,但考虑到对管道气密性等性能的影响,评价时规定燃气管道点蚀穿孔直径不能大于50 mm。对含面蚀缺陷的燃气管道进行完整性结构强度评价时,需要按照燃气管道的压力级别分别考虑:对于中低压燃气管道,主要考虑外载荷的作用,以管道的变形作为外载荷承载能力的评价依据;对次高压燃气管道,分别考虑内压和外载荷的作用,分别以管道的变形和管道缺陷处的应力作为管道承载能力的评价依据;对高压燃气管道,主要考虑内压的作用,以管道缺陷处的应力作为内压承载能力的评价依据。对于含面蚀缺陷的中低压和次高压燃气管道,需要做外载荷的承载能力评价。分析面蚀缺陷的长度、宽度、深度和位置对管道变形的影响。创新性地研究出含面蚀缺陷管道外载荷承载能力评价数学模型,并采用试验验证了该数学模型的正确性。当选择内压承载能力评价方法时,推荐采用ASME B31G-2009方法评价含面蚀缺陷燃气管道承受内压的能力。本文仅针对燃气管道完整性评价中含腐蚀缺陷的管道强度评价开展研究。建议在今后的研究中继续拓宽研究对象,开展裂纹、凹陷和焊缝缺陷等其他缺陷的管道完整性评价方法研究。
Based on the Spangler-lowa method,combined with finite element modeling,statistical analysis,mathematical fitting and experimental verification and so on,the external load carrying capacity and internal pressure carrying capacity of the defective pipeline are studied. For the evaluation of the external load carrying capacity of the intact pipeline,the Spankler-lowa method was used to calculate the horizontal diameter deformation of the pipeline,and then the horizontal deformation rate of the pipeline was obtained. When the horizontal diameter deformation rate of the pipeline exceeds 3%,the pipeline is considered to be ineffective. Evaluation of external load carrying capacity of the pipeline with uniform corrosion defects is as follows:the pipeline with small diameters (outer diameter ≤ 700 mm) can be evaluated according to the minimum nominal wall thickness specified in GB 50028-2006;and the pipeline with large diameters (outer diameter > 700 mm)) should be evaluated according to the calculation results of the Spangler-lowa method. The pitting defect has little effect on the deformation of the pipeline affected by the external load. However,considering the influence on the airtightness and other performance of the pipeline,the pitting perforation diameter of the gas pipeline specified in the evaluation cannot be not more than 50 mm. When evaluating the integrity structural strength of gas pipeline with surface corrosion defects,it is necessary to consider the pressure levels of gas pipelines respectively. For medium and low pressure gas pipelines,the effect of external load is mainly considered,and the deformation of pipeline is used as the evaluation basis of external load carrying capacity. For the sub-high pressure pipeline,the effects of internal pressure and external load are considered respectively,and the deformation and stress of the pipeline are used as the evaluation basis of the carrying capacity of the pipeline. For the high-pressure gas pipelines,the effect of the internal pressure is mainly consi
作者
马彬
江枫
马旭卿
MA Bin;JIANG Feng;MA Xuqing
出处
《煤气与热力》
2019年第5期32-39,10043,10044,共10页
Gas & Heat
关键词
城市燃气管道
完整性评价
含缺陷管道
点蚀
面蚀
承载能力
city gas pipeline
integrity evaluation
defective pipeline
pitting
surface corrosion
carrying capacity
